1. Field of the Invention
The present invention relates to an electrical connector, and particularly to an electrical connector for signal transmission between two separated circuit boards.
2. Description of Related Art
Card edge connectors are widely used to connect daughter cards or other similar electronic components with mother boards. Referring to FIGS. 7-9, a conventional card edge connector 100 for connecting a daughter card 200 with a mother board 300 includes an elongate housing 101 and a plurality of contacts 102. The housing 101 defines a mating port 103 and a plurality of apertures 104 in a front face thereof, and a plurality of passageways 105 communicating with the mating port 103 and the apertures 104. Each of the contacts 102 includes a retention portion 106 received in a slot 111 communicating with a corresponding one of the passageways 105, a resilient arm 107 forwardly and downwardly extending from the retention portion 106 and received in the corresponding one of the passageways 105, a curved portion 108 extending from the resilient arm 107 and exposed into the mating port 103 to function as a contact portion, a distal end 109 bent from the curved portion 108 and received in a corresponding aperture 104, and a tail portion 112 downwardly and rearwards extending from the retention portion 106 and soldered to a solder pad 301 of the mother board 300. In order to increase the mating force between the curved portions 108 of the contacts 102 and conductive pads 201 of the daughter card 200 for ensuring a reliable electrical connection therebetween, the distal ends 109 of the contacts 102 are usually preloaded by a support portion 110 of the housing 101.
However, since the distal ends 109 of the contacts 102 exert reaction force on the support portion 110, a middle portion of the housing 101 above the mating port 103 will sag due to the elevated temperature during the reflow process of connecting the contacts 102 to the mother board 300. The elevated temperature results in tending to close the mating port 103, thereby damaging the card edge connector 100 (shown in phantom lines in FIG. 7). A solution for the above problem is to put a cover 400 in the mating port 103 to support the support portion 110 during the reflow process. Nevertheless, the additional cover 400 increases the cost of the card edge connector 100. In addition, the cover 400 has to be removed before the insertion of the daughter card 200 into the mating port 103 of the card edge connector 100, thereby complicating the assembly of the card edge connector 100 and the daughter card 200.
Hence, an improved electrical connector is required to overcome the disadvantages of the conventional card edge connector.